Conventional color photographic images are formed via a chromogenic development process. After exposure of a color photographic element, the object scene is stored as a composite of red, green, and blue latent silver halide images. During processing, these images are reductively developed in presence of a developer. Oxidized developer produced under these conditions reacts with cyan, magenta or yellow dye-forming deprotonated couplers to give their respective dyes. The composite dye image is then formed by the superpositioning of the cyan, magenta and yellow dye images to afford a reproduction of the original scene.
An important feature of photographic reproductions is their image stability. The stability of a color image is clearly dependent upon the stability of its component dyes. Pictures held in the dark, that is, stored in albums, boxes or slide trays and not exposed to direct light, degrade primarily via hydrolytic thermal mechanisms. Images exposed to light, on the other hand, degrade via both photochemical and such hydrolytic mechanisms. The importance of photochemical fade depends largely on the extent to which the image is exposed to light. It is apparent from these considerations that the photolytic stability of photographic dyes is of prime importance to image stability.
Yellow couplers comprising acylacetamide groups with a heterocycle bonded to the acyl group are shown in U.S. Pat. No. 5,674,667 and in copending application U.S. application Ser. No. 09/069,651 filed Apr. 29, 1998. Although such couplers provide desirable properties, the dyes formed therefrom are more sensitive to photolytic or light degradation than is desired.
It has been found now that certain new 2-alkoxyaryl-substituted heterocyclic-acetanilide yellow couplers can afford yellow azomethine dyes with improved photolytic stabilities, over that provided by previously described heterocyclic-acetanilide couplers